Production of vinyl chloride from cracked hydrocarbon gases containing acetylene



KE NETH A. K095,

RALPH E'- lY/v/v, J

INVENTORS.

HWm m Z YL CHLORIDE FROM CRACKED Filed Jan. 18, 1954 K. A. KOBE ET ALPRODUCTION OF VIN April s, 1958 ATTOQNEY- PRODUCTION OF VINYL CHLORIDEFROM CRACKED HYDROCARBON GASES CON- TAINING ACETYLENE Kenneth A. Kobe,Austin, Tex., and Ralph E. Lynn, Jr., Cuyahoga Falls, Ohio ApplicationJanuary 18, 1954, Serial No. 404,715 14 Claims. c1. 260-6 56) Thisinvention has to do generally with the production of vinyl chloride, andis directed particularly to a novel process for vinyl chloride formationin situ within hydrocarbon gas mixtures containing hydrogen andordinarily low concentrations of acetylene,

The increasing importance of monomeric vinyl chloride arises because ofits utility as a synthesis compound from which various products ofexpanding applicability, and notably the polyvinylresins, can be made.One of the established methods for making vinyl chloride is by thereaction of acetylene with hydrogen chloride, using catalyst such as themetallic halides, e. g. halides of mercury, copper and barium, and ofwhich mercuric chloride appears to have had preference. ,Ordinarily theacetylene used will have been obtained in a relatively pure condition,as by separation from. a gas mixture or :as derived from acetylenesynthesis conducted especially for reaction of the acetylene andhydrogen chloride to vinyl chloride.

From various sources may be obtained hydrogencontaining gases havingconcentrations of acetylene so low as to render relatively uneconomicalor competitively :too expensive a separation of the acetylene for vinylchloride production. Particular sources for such gases, :and which lendthemselves advantageously and economic- .ally to the present processgarethe highly cracked hydrocarbon gases produced by the known Schochprocess (see Acetylene from Hydrocarbons, University of TexasPublication No. 5011, Austin, Texas, June 1950), the

'Wulff process (see Industrial and Engineering 'Chemiistry, vol. 45, N0.12, pp. 2596-2606; December 1953),

and the Sachse process (see U. S. Dept. Commerce; FIAT report No. 988,P. B. 67790; 1947).

The following table gives typical gas compositions as obtained fromthese processes:

Sachse Process, N at. .Gas,

- mole Wulfi Process Component Nat. Gas,

mole percent Propane,

mole 7 percent Carbon monoxide Nltrogen Oxygen This invention has forone of its primary objects the conversion of. substantially 'the' entireacetylene content of such gases to vinyl chloride. in amannerobviatinganynecessity for pro-separation of the acetylene, and by for percentination of the vinyl chloride directly in the gaseous mix- ,ture..Specifically contemplated 'is .a novel procSsdistinguishingrtheinvention from all prior practices of which we are aware, whereby thehydrogen and. acetylene con- 2,830,102 Patented Apr. '8, 1958 tents ofthe same gas stream are used in conjunction with chlorine addition tothe gas, to form sequentially hydrogen chloride and vinyl chloride, allin situ within the gas stream and by a continuous process.

In further reference to the gas composition, the invention ispracticably applicable to vinyl chloride formation in gases consideredto be very dilute as to acetylene, e. g. containing as low as around 3mole percent. The utility of the process of course applies also to gasesof higher acetylene content, c. g. where the acetylene content might beas high as 20 mole percent. However, the invention is primarily directedto use of those gases containing acetylene in such dilute concentrationsas re-. quire the aforesaid in situ formation of hydrogen chloride forpracticably economical use of the acetylene for vinyl chlorideproduction. The hydrogen content of the gas may vary, as'for examplebetween 30-60 mole percent, and is not of primary importance so long asthere is present in the gas being reacted with the chlorine, sufficienthydrogen to produce the amount of hydrogen chloride required forreaction with all the acetylene.

The present process involves the first step of introducing chlorine intothe gaseous mixture and reacting the chlorine with hydrogen in the gasto convert preferably all the chlorine to hydrogen 'chloride. Thisreaction being highly exothermic, the temperature increase may besufficient to crack some of the hydrocarbons in the gas mixture in amanner productive of appreciable quantities of acetylene over theinitial acetylene content of the gas. The reaction also will ordinarilyresult in some formation of carbon, and relatively heavy unsaturatedhydrocarbons which may be separated to avoid contamination in thesubsequent stage.

The gaseous mixture with its hydrogen chloridecontent is then contactedwith a suitable catalyst, preferably under controlled temperatureconditions, which promotes the acetylene-hydrogen chloride reaction tothe point of substantially complete conversion to the vinyl chloridemonomer of the entire acetylene content of the gas. It will beunderstood that the invention contemplates the use of any suitablecatalyst for effecting the hydrogen chloride reaction, for example, themetallic (notably mercury) halides, particularly mercuric chloride, andmixtures thereofwithother metal catalysts which the patent and otherliterature shows to be well known for catalyzing this reaction.

The converted gas mixture may be given any suitable tinal treatment, asby absorption and fractionation, for separation of the vinyl chloride.Those familiar with the art will recognize the applicability ofconventional methods and apparatus for this purpose.

The invention and further details concerning its operation will beunderstood more fully from the following description of the accompanyingdrawing which shows an illustrative embodiment in a process operatingsequentially to convert the hydrogen content of a diluteacetylene-containing hydrocarbon gas to hydrogen chloride, and theneffect in the presence of a catalyst, the acetylene-hydrogenchloridereaction to form vinyl chloride.

Referring tothe drawing, a dilute acetylene-containing hydrocarbon gasof the composition order referred to in the foregoing, preliminarily maybe scrubbed free of solid materials and introduced through line 10 to areaction chamber or burner 11 which is fed through line 12 with chlorinegas in an amount suificient for reaction with the hydrogen content ofthe hydrocarbon gas stream, to produce hydrogen chloride in quantitiessufficient for conversion of the acetylene content of the hydrocarbongas.- In starting the operation, an independent heating means, typicallyan electrical heating element 13, may function in the burner chamber toinitiate the hydro gen" and chlorine reaction, following which thereaction is self-continuing because of its highly exothermic nay ture,giving e.. g. a burner chamber outlet temperature between350 F. to 700F. The temperatures in the that the gas stream in line 29 may beintroduced to an absorber '32 and'therein contacted with a solvent forvinyl chloride introduced through line 33 and acting to remove from thegas its vinyl chloride, the rich abflarne itself may be sufficientlyhigh, 'for example in ex- 5 sorbent being removed through line 34. Theresidual cess of 1500 F., to produce further cracking of the gases areremoved through line 35 forfurther treatment. hydrocarbons and theproduction of appreciable quan- Vinyl chloride is recovered from therich solution by the tities of acetylene in addition to that containedin the use of heat and/or reduced pressure and the clean solvent burnerfed stream. is recycled to line 33.

Leaving the burner through line 14 the hydrogen 1 The described processmay be operated under ordinary chloride-containing hydrocarbon gasstream may be pressures, controllable for example by the valve 36'which' given any suitable treatmentin advance of the catalyst may rangefor example between 1 to 30 atmospheres abreactor, for the removal ofcarbon and otherimpurities solute. produced by the high temperaturereaction in the burner. In operation of the process we have usedcatalyst in and also if desired for cooling the gas stream to within theform of a complex chloride supported on activated a temperature rangemost desirable for eflicient convercarbon prepared according to thefollowing formulation: sion in the reactor. Merely as illustrative, thegas stream is shown to be discharged from the burner through a grams Wzlguvated carbon carbon separator generally indicated at 15, which maygrams g l comprise a shell 16 containing a plurality of bag or 559grlams g 6 on a other type filters 17 through which the gas passes tolsoom F the outlet line 18, and within which the carbon is retained forsettling out into the base of the, shell and The barium. chloride andmercuric chloride were disremoval through line 19. The gas leaving theseparator solved in the water-methanol solution. The presence of may bepassed through lines 20 and 21 to the catalyst the barium chloridegreatly increased the solubility of reactor generally indicated at 22,or where it is desired the mercuric chloride. If mercuric chloride waspresent to cool the gas, some or all of the gas may be passed alone,solution could be achieved only by heating to the throughline 23 andcooler 24. When using in the reboiling point. This phenomenon confirmedthe belief actor mercuric chloride catalyst of the type commonly that acomplex of mercuric-barium-chloride'was formed. used for acetyleneconversion by reaction of hydrogen 0 The methanol was used in theformulation to obtain a chloride to produce vinyl chloride, the gasstream may deeper penetration of the complex into the pores of the becooled so that it enters the reactor within a range of activated carbon.about 200 F. to 400 F. The solution of the complex salt was poured, withThe reactor 22 may be of any suitable design permitagitation, over theactivated carbon. There 1 was just ting intimacy of contact of thecatalyst contained within enough of the solution to thoroughly wet thecarbon. the reactor shell 25 by the gas stream introduced from Themixture was then dried over a steam-bath for two line 21. Merely asillustrative, the reactor shell is hours and finally in an oven at 105C. for 24 hours. shown to contain a plurality of tubes 26 terminating inThe following tabulation shows the results obtained in sheets 27 andfilled with the catalyst 28 so that the gas a series of typical runsemploying oil-washed Schoch stream fiows downwardly through the catalystcolumns feedgas, with the reactor temperature maintained at to theoutlet line 29. The acetylene-hydrogen chloride about 180 C.

' 02H: Conver- Space Mixture, 02H), CzHz, Oh, Total, Excess inExit sion,Yield Velocity S O. F. M. percent S C.F.M. S.O.F.M. S.O.F.M. H01, Gas,percent in percent percent Catalyst 11. 1 0.117 0. 076 1.126 30 0. 1498. 9 294 11.1 0. 131 0.085 1. 200 30 0. 24 98. 2 94 329 10. e 0. 111 0.070 1. 20 0.15 98. 8 80 292 10. 9 0. 128 0.078 1. 253 22 0. 00 97. 0 91327 10. 9 0. 143 0.086 1. 396 20 0. 51 96. 0 100 304 10. 9 0. 159 0.090 1. 550 21 0. 79 03. s 109 404 10.0 0.174 0.100 1.702 22 1.01 92.0117 444 11.0 0.184 0.111 1.781 20 1.31 89.8 I 121 405 1 Yield is gramsvinyl chloride produced per liter catalyst per hour.

reaction catalyzed in the reactor being exothermic, ordinarily it willbe desired to control or limit the temperatures in the catalyst as bypassing a cooling fluid from the inlet 30 to the outlet 31 through thereactor in contact with the tubes 26. Generally speaking, thetemperature of the gas stream in the reactor "may be confined within therange of about 200 F. to400 F.

The resulting gas stream may be subjected to any suitable furthertreatment for separation of its vinyl produced by washing Schochelectric discharge process gas with oil to remove higher acetylene andadding approximately 30 mole percent carbon monoxide. 'It was chloridecontent. This may be done for example using 35 found that'the carbonmonoxide did not appreciably aifect conventional absorption andfractionating methods and the operation of the process as shown by thefollowing equipment. For present purposes it will suffice to'indicatetypical examples of tests conducted at C.:

01H; Conver- 01H: ure, CjHg; 00, 01,, Total, in Exit sion, Yield 8 aceSpace 5 0.1. M. S.O.F.M. S.C.F.M. 5.0.111. S.0.F.M. Gas, percent Veoclty Va ocity percent 1 Yield-grams vinyl chloride per liter catalystper hour.

We claim: 1

1. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises adding chlorine to said stream'and'reacting the chlorinewith hydrogen in the gas to produce hydrogen chloride in a hot gasstream heated by the exothermicchlorine-hydrogen reaction, contactingthe resulting gas mixture with a catalyst and thereby reacting thehydrogen chloride with the acetylene content of the gas to produce vinylchloride, and separating the vinyl chloride from the residual gasmixture.

2. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises adding chlorine to said stream and reacting the chlorinewith hydrogen in the gas to produce hydrogen chloride and carbon in ahot gas stream heated by the exothermic chlorine-hydrogen reaction,separating the carbon from the gas, contacting the resulting gas mixturewith a catalyst and thereby reacting the hydrogen chloride with theacetylene content of the gas to produce vinyl chloride, and separatingthe vinyl chloride from the residual gas mixture.

3. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises adding chlorine to said stream and reacting the chlorinewith hydrogen in the gas to produce hydrogen chloride in a hot gasstream heated by the exothermic chlorine-hydrogen reaction, cooling thegas, contacting the resulting gas mixture with a catalyst and therebyreacting the hydro gen chloride with the acetylene content of the gas toproduce vinyl chloride, and separating the vinyl chloride from theresidual gas mixture.

4. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises adding chlorine to said stream and reacting the chlorinewith hydrogen in the gas in a zone to produce hydrogen chloride in a hotgas stream heated bythe exothermic chlorine-hydrogen reaction,withdrawing the gas from said zone at a temperature between about 350 F.to 700 F., contacting the resulting gas mixture with a catalyst andthereby reacting the hydrogen chloride with the acetylene content of thegas to produce vinyl chloride, and separating the vinyl chloride fromthe residual gas mixture.

5. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises adding chlorine to said stream and reacting the chlorinewith hydrogen in the gas to produce hydrogen chloride in a hot gasstream heated by the exothermic chlorine-hydrogen reaction, contactingthe resulting gas mixture with a catalyst at a temperature between about200 F. to 400 F. and thereby reacting the hydrogen chloride with theacetylene content of the gas to produce vinyl chloride, and separatingthe vinyl chloride from the residual gas mixture.

6. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises add-' ing chlorine to said stream and reacting thechlorine with hydrogen in the .gas in a zone to produce hydrogenchloride in a hot gas stream heated by the exothermic chlorine-hydrogenreaction, withdrawing the gas from said zone at a temperature betweenabout 350 F. to 700 F.-, contacting the resulting gas mixture with acatalyst at a temperature between about 200 F. to 400 F. and therebyreacting the hydrogen chloridewith the acetylene content of the gas toproduce vinyl chloride, and separating the vinyl chloride from theresidual gas mixture.

7. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises addi ing chlorine to said stream and reacting thechlorine with hydrogen in the gas to produce hydrogen chloride in a hotgas stream heated by the exothermic chlorine-hydrogen reaction,contacting the resulting gas mixture with a catalyst and thereby.reacting the hydrogen chloride with the acetylene content of the gas toproduce vinyl chlo ride, separating the vinyl chloride from the residualgas mixture, and conducting said reactions under pressure between about1 to 30 atmospheres absolute.

8. The method of producing vinyl chloride from a cracked hydrocarbon gasstream containing hydrogen and a relatively low quantity of acetylene,that comprises adding chlorine to said stream and reacting the chlorinewith hydrogen in the gas in a zone to produce hydrogen chloride in a hotgas stream heated by the exothermic chlorine-hydrogen reaction,withdrawing the gas from said zone at a temperature between about 350 F.to 700 F., contacting the resulting gas mixture with a catalyst at atemperature between about 200 F. to 400" F. and thereby reacting thehydrogen chloride with the acetylene content of the gas to produce vinylchloride, separating the vinyl chloride from the residual gas mixture,and con ducting said reactions under pressure between about 1 to 30atmospheres absolute.

9. The method as defined in claim 1, in which the catalyst contains amercury halide.

10. The method as defined in claim 7, in which the catalyst containsmercuric chloride.

11. The method of producing vinyl chloride from a cracked hydrocarbongas stream containing hydrogen and a relatively low quantity ofacetylene, that comprises adding chlorine to said stream and reactingthe chlorine with hydrogen in the gas under temperature and pressureconditions causing formation of hydrogen chloride and also conversion ofhydrocarbons in the gas to acetylene in a hot gas stream heated by theexothermic chlorine-hydrogen reaction, contacting the resulting gasmixture with a catalyst and thereby reacting the hydrogen chloride withthe acetylene content of the gas to produce vinyl chloride, andseparating the vinyl chloride from the residual gas mixture.

12. The method of producing vinyl chloride from a cracked hydrocarbongas stream containing hydrogen and a relatively low quantity ofacetylene, that comprises adding chlorine to said stream and reactingthe chlorine with hydrogen in the gas under temperature and pressureconditions causing formation of hydrogen chloride and also conversion ofhydrocarbons in the gas to acetylene in a hot gas stream heated by theexothermic chlorine-hydrogen reaction, contacting the resulting gasmixture with a catalyst and thereby reacting the hydrogen chloride withthe acetylene content of, the gas to produce vinyl chloride, separatingthe vinyl chloride from the residual gas mixture, and conducting saidreactions under pressure be- I tweena'bout 1 to 30 atmospheres absolute.

13. The method of producing vinyl chloride from a cracked hydrocarbongas stream containing hydrogen and a relatively low quantity ofacetylene, that comprises adding chlorine to said stream and reactingthe chlorine with hydrogen in the gas to produce hydrogen chloride in ahot gas stream heated by the exothermic chlorine-hydr'o gen reaction,then separating carbonaceous residue from the gas, contacting theresulting gas mixture with a catalyst and thereby reacting the hydrogenchloride with the acetylene content of the gas to produce vinylchloride, and separating the vinyl chloride from the residual gasmixture.

14. The method of producing vinyl chloride from a cracked hydrocarbongas stream containing hydrogen and a relatively low quantity ofacetylene, that comprises adding chlorine to said stream and reactingthe chlorine with hydrogen in the gas in a zone to produce hydrogenchloride in a hot gas stream heated by the exothermic chl0-rinerhydrogenl reaction, withdrawing; the gas tram said? ReferencesCited in the file of this patent zone at a temperature, between about350 F. to 701)? F1, UNITED; STATES; PATENTSl y then separating:canhonaceous residue from the: gas con -;1 g v A l V tact'mg theresultinggas mixture-with a catalyst at a tem-- 2 7 Q g" 9 3 perature;between, about 200 F. to 400 F. and thereby 55 2,705,732 Bmwnm" at 1955reacting the hydrogen chloride with the acetylene content 7 Y FOREIGNPATENTS of the gas to produce vinyl chloride, and separating the780,057; France 18, 1935 vinyl chloride from the residual gas mixture.

1. THE METHOD OF PRODUCING VINYL CHLORIDE FROM A CRACKED HYDROCARBON GASSTREAM CONTAINING HYDROGEN AND A RELATIVELY LOW QUANTITY OF ACETYLENE,THAT COMPRISES ADDING CHLORINE TO SAID STREAM AND REACTING THE CHLORINEWITH HYDROGEN IN THE GAS TO PRODUCE HYDROGEN CHLORIDE IN A HOT GASSTREAM HEATED BY THE EXOTHERMIC CHLORINE-HYDROGEN REACTION, CONTACTINGTHE RESULTING GAS MIXTURE WITH A CATALYST AND THEREBY REACTING THEHYDROGEN CHLORIDE WITH THE ACETHYLENE CONTENT OF THE GAS TO PRODUCEVINYL CHLORIDE, AND SEPARATING THE VINYL CHLORIDE FROM THE RESIDUAL GASMIXTURE.